Classifications

• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
  • C09D4/00—Coating compositions, e.g. paints, varnishes or lacquers, based on organic non-macromolecular compounds having at least one polymerisable carbon-to-carbon unsaturated bond ; Coating compositions, based on monomers of macromolecular compounds of groups C09D183/00 - C09D183/16
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
  • C08F290/00—Macromolecular compounds obtained by polymerising monomers on to polymers modified by introduction of aliphatic unsaturated end or side groups
  • C08F290/08—Macromolecular compounds obtained by polymerising monomers on to polymers modified by introduction of aliphatic unsaturated end or side groups on to polymers modified by introduction of unsaturated side groups
  • C08F290/14—Polymers provided for in subclass C08G
  • C08F290/148—Polysiloxanes
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
  • C09D183/00—Coating compositions based on macromolecular compounds obtained by reactions forming in the main chain of the macromolecule a linkage containing silicon, with or without sulfur, nitrogen, oxygen, or carbon only; Coating compositions based on derivatives of such polymers
  • C09D183/04—Polysiloxanes
  • C09D183/06—Polysiloxanes containing silicon bound to oxygen-containing groups
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
  • C09D4/00—Coating compositions, e.g. paints, varnishes or lacquers, based on organic non-macromolecular compounds having at least one polymerisable carbon-to-carbon unsaturated bond ; Coating compositions, based on monomers of macromolecular compounds of groups C09D183/00 - C09D183/16
  • C09D4/06—Organic non-macromolecular compounds having at least one polymerisable carbon-to-carbon unsaturated bond in combination with a macromolecular compound other than an unsaturated polymer of groups C09D159/00 - C09D187/00
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T428/00—Stock material or miscellaneous articles
  • Y10T428/31504—Composite [nonstructural laminate]
  • Y10T428/31652—Of asbestos
  • Y10T428/31663—As siloxane, silicone or silane

Definitions

• This invention relates to release coating compositions, and, more particularly, to TJV-curable liquid compositions of predetermined viscosity containing an acrylate-functional silicone resin and a miscible vinylether .
• Release coatings are substances which control or eliminate the adhesion between two surfaces. Often, curing of the liquid release coating is accomplished by solvent removal and thermal crosslin ing. Radiation curable release coatings, on the other hand, contain no solvent and have the unique ability to be cured at, or slightly above, room temperature. Polymerization is initiated by ultraviolet light (UV) or electron beam (EB) exposure. Most commercial radiation curable release coatings are based on polydimethylsiloxane resins which have been functionalized with reactive groups.
• Vinylethers are effective reactive diluents for epoxy functional silicones in cationic release coating systems . Vinylethers are also known to be effective reactive diluents for urethane and epoxy acrylate oligomers in free radical and hybrid wood coating formulations . SUMM7ARY OF THE INVENTION
• vinylethers are used as reactive diluents for acrylate functional silicones in release coating systems. What has been discovered is that vinylethers are surprisingly effective diluents in these systems and can be used to decrease the? solution viscosity, control the level of release, and reduce the cost of such formulations.
• the invention is directed to a radiation curable release coating composition
• a radiation curable release coating composition comprising, by weight,
• (b) is miscible with (a) and reduces the viscosity of the composition to a viscosity of about 100-2000 cps .
• Component (b) preferably is present in an amount of about 10-50% by weight of the composition, which is curable in air with a free radical or cationic photoinitiator, or both;
• (c) is present in an amount of about 3 phr; and
• (a) is an acrylate functional polydimethyl silicone.
• the vinylether monomers used herein were obtained from International Specialty Products, Inc. (see TABLE I elow) .
• Acrylate functional silicones (RC 726 and RC 708) were obtained from the Goldschmidt Chemicals Corporation, lodonium salt cationic photoinitiators were obtained from GE Silicones (UV9380C) and Rhone-Poulerit: (PC-702) .
• the free radical photoinitiator (Darocur 1173) , was obtained from Ciba Additives Division.
• Melinex ® 505 polyethylene terephthalate (PET) film was obtained from ICI Americas Inc. Cold rolled steel panels were obtained from the Q-Panel Company.
• the adhesive tapes are manufactured by the 3M Company, Tesa Corp., and Johnson & Johnson.
• DDVE 'V dodedcyl vinylether The compatibility of vinylethers in silicone fluids was determined by blending the desired ratio of components with slight heat . The mixtures were then allowed to stand overnight and observed in the morning for any sign of phase separation.
• Release coating formulations were prepared by mixing the components in an amber vial. A uniform coating of the desired coating thickness was then " "applied to the PET substrate using a #3 Mayer bar applicator. The liquid coating was cured by exposure to UV irradiation using an AETEK Model QC 1202A/N UV Processor containing two 200 Watt/inch medium pressure mercury vapor lamps. The UV exposure was accomplished either under air or nitrogen as indicated.
• Tack-free time was defined as the maximum conveyor speed (i.e. - minimum UV dose) which can be used to produce a coating that is dry to the touch immediately after UV exposure. Rub-off was determined by rubbing the cured coating under gentle finger pressure. Any loss of adhesion or 'balling up 1 of the coating was considered a failure .
• Quantitative measurements of release and subsequent adhesion were obtained using a Gardner Slip/Peel Tester. Coatings were cast on the PET substrate and cured by UV exposure. After 24 hours, the specified tape was applied to the surface and a 5 pound rubber roller was rolled over the tape 5 times. Release was determined by measuring the force, in grams per linear inch, required to remove the tape at an angle of 180 degrees at a speed of 1 fpm. After the tape was removed from the release coating, the subsequent adhesion was determined by reapplying the tape to a clean steel panel, rolling 5 times with the rubber roller, and again measuring the force required to remove the tape at an angle of 180 degrees. A minimum of 5 trials were conducted on each sample and the mean reported.
• Aged release was determined by placing the cured sample in an oven at 70 C for 20 hours prior to applying the test tape and measuring the release as described above .
• Example 4 The performance of an acrylate functional silicone (RC-726) containing 3 phr (parts per hundred resin) of the free radical photoinitiator Darocure 1173, (Example 2) , was compared to the same formulation modified by adding 15 wt% CHVE, (Example 3) .
• Example 3 was repeated except that 0.3 phr (3 phr based on CHVE) of a cationic photoinitiator (UV9380C) was incorporated (Example 4) .
• Each formulation was applied to polyester and cured under nitrogen using the AETEC 1202 UV processor. In each case, the maximum cure speed was 50 fpm. Release properties were measured versus Johnson & Johnson Zonas surgical tape on coatings cured at 40 fpm.
• UV cure can be readily accomplished in air.
• a formulation containing 80 weight % DDVE, 10 weight % CHVE and 10 weight % silicone acrylate with 1.2 parts of Darocure 1173 and 1.2 parts UV9380C was readily cured at 40 fpm (1000 mJ/cm ) in either air or nitrogen. This is a significant finding considering the high cost of maintaining a nitrogen atmosphere.
• vinylethers are effective reactive diluents for acrylate functional silicone resins.
• CHVE is an effective control release additive while the monovinylethers CVE, EHVE, and DDVE can be used alone, or in conjunction with CHVE, to modify initial release and improve subsequent adhesion and aged release.
• hybrid formulations containing both a free radical and cationic photoinitiator can be readily cured in air thus avoiding the high expense associated with nitrogen inerting.

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• Chemical & Material Sciences (AREA)
• Organic Chemistry (AREA)
• Life Sciences & Earth Sciences (AREA)
• Engineering & Computer Science (AREA)
• Materials Engineering (AREA)
• Wood Science & Technology (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Medicinal Chemistry (AREA)
• Health & Medical Sciences (AREA)
• Polymers & Plastics (AREA)
• Paints Or Removers (AREA)
• Macromonomer-Based Addition Polymer (AREA)
• Polymerisation Methods In General (AREA)
• Treatments Of Macromolecular Shaped Articles (AREA)
• Compositions Of Macromolecular Compounds (AREA)
• Adhesives Or Adhesive Processes (AREA)

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• 1997
  • 1997-10-09 US US08/948,208 patent/US6011079A/en not_active Expired - Lifetime
• 1998
  • 1998-09-10 JP JP2000515941A patent/JP4146996B2/ja not_active Expired - Fee Related
  • 1998-09-10 WO PCT/US1998/018806 patent/WO1999019371A1/en not_active Ceased
  • 1998-09-10 DE DE1998620284 patent/DE69820284T2/de not_active Expired - Fee Related
  • 1998-09-10 AT AT98948126T patent/ATE255600T1/de not_active IP Right Cessation
  • 1998-09-10 EP EP19980948126 patent/EP1023332B1/de not_active Expired - Lifetime
  • 1998-09-10 AU AU94761/98A patent/AU9476198A/en not_active Abandoned

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